This invention is generally directed to the testing of electronic products by utilizing test equipment operating in response to instructions transmitted from a computerized test system. This invention more specifically addresses a computer controlled test system which minimizes the need to change a test program in response to a change of the specific test equipment to be used.
Test instruments operating in response to digital instructions generated by a personal computer (PC) facilitates the testing of electronic products connected to the test instruments. In a conventional system, a plurality of instructions are sent from the PC in accordance with predetermined program steps to particular test instruments in order to perform a test. The PC receives data from the test instruments indicative of the results of the test. Thus, the programming of the PC to implement such conventional test procedures depends on the specific test instruments to be utilized. Such a system provides generally good results with regard to testing electronic products as long as the specific test instruments for which the test system was originally programmed are utilized.
However, such test systems place significant burdens upon the test equipment designer when the test sequence has to be altered or when different test instruments have to be utilized which are not identical to the original test instruments. For example, the substitution of a digital multimeter manufactured by one vendor for a digital multimeter manufactured by a different vendor would typically require substantial revisions to the program, e.g. the sending of different instructions to the different multimeter and possibly the use of a different communication protocol to communicate with the different multimeter. This requires a substantial effort by the test equipment designer to merely accommodate the substitution of one multimeter with a different multimeter even though no functional changes were made in the testing of the electronic equipment.
Attempts have been made to improve the methodology by which computerized test routines are constructed. For example, National Instruments provides a software package known as "LabVIEW". This software is a graphical programming package in which icons are used to denote programs and subroutines. These icons are cascaded together to build an interface which will allow a particular test instrument to make a test or to cause the instrument to take an action. While such efforts have helped test designers in the design and development of test programs, significant difficulties still remain which impair the designer's ability to accommodate different test instruments.